[aprssig] backup pwr systems

[A.J. Farmer (AJ3U)]

On 12/10/06, Joel Maslak <jmaslak-aprs at antelope.net> wrote:
> That said, it's good to not charge batteries too quickly.
>
> (nor do I recommend using a car battery - they don't do deep
> discharge well)

Batteries can be charged quickly, if done properly.

A car is designed to run with a functioning alternator all the time.
If the alternator fails, the battery will not last long.  The
battery's main function is there to power the starter to start the
car.  In our application, we want to use a deep cycle battery that
picks up the load when the main power supply fails.  The battery needs
to permit a deep discharge and long runtime, and therefore requires a
charger which can supply a large charge current to bring it back in a
reasonable time once the power returns.

You are right, the electrical theory is the same, however the tools
used and goals involved are much different.

-- 
A.J. Farmer, AJ3U
http://www.aj3u.com